"Dressing" is the word used to describe the process of profiling a grinding wheel of the type used in a "form grinding" operation. Dressing is necessary because in form grinding the grinding wheel is required to have the reverse form of what is required on the workpiece. The process of grinding then transfers the required form unto the workpiece.
The process of "form grinding" is used in the manufacture of a large variety of accurate and complex shapes in the metal working industry. It is also used to manufacture precision spur and helical gears.
The dressing of the grinding wheel is carried out by means of a rapidly rotating metallic wheel, called a dressing wheel. While the grinding wheel and the dressing wheel are rotated, the dressing wheel is guided through a predetermined path corresponding to the desired form to be imparted to the periphery of the grinding wheel. As the dressing wheel moves through the defined path successively in identical cycles of motion, the grinding wheel is fed into it in equal increments between cycles. Conversely, the dressing wheel may be made to execute subsequent paths with an incremental shift towards the grinding wheel between successive cycles of motion.
There are two distinct problems involved in dressing or profiling a grinding wheel which can be described as the "initial dress problem" and the "redress problem".